Construction makes use of studs either of wood or metal. Metal studs are greatly preferred in many forms of construction, since they are resistant to termites, rot and fire damage. Metal studs are lighter than wooden studs, of equal strength, and are thus suitable for non-loadbearing walls and partitions in commercial buildings. In high rise buildings they are preferred, or even required by architects and engineers, in order to avoid excessive weight in the building.
Metal studs support wall covering materials and are frequently used in association with panels of drywall material. Walls also carry services such as wiring, and the like.
It is desirable that the walls shall readily pass services to and fro without obstruction.
In any metal stud it is desirable to reduce the effects inherent in the use of metal, such as transfer of heat, and transfer of sound. Heat loss is a significant problem in exterior walls. Various proposals have been made to provide studs for exterior walls, in which the path for heat transfer has been reduced by forming openings in the stud.
In interior walls, the studs should be as free as possible from sound transfer. It is also desirable that they shall be as rigid as is required to maintain the panels in position, and also to be as light as possible.
In the past, typical metal drywall studs involved a generally three sided channel section having a central web and two side walls, bent into a channel shaped cross-section. This section was continuous along the length of the studs.
These studs have been widely used in the past and have proved satisfactory in many cases. There are however various disadvantages which arise from this particular design. In the first place the central web is generally speaking a continuous barrier throughout the height of the wall. Consequently, it is necessary to puncture the web in order to pass wiring through it. This tends to leave relatively sharp edges, and also involves a certain amount of time consuming work in punching the holes.
Another disadvantage is the fact that unless such studs were made of extremely thin gauge metaal, they tended to be unecessarily heavy, and costly for the job to be done.
In order to overcome some of these problems the studs were in some cases designed with service openings. However, these tended to weaken the stud and make it less rigid, and such holes could only be opened up in a very restricted manner.
In addition, it is desirable if possible to have a stud which has the same overall dimensions as a regular 2.times.4 stud. However, for reasons of economy and the like, it has been the practice to reduce the width of the web of the metal stud, so that the end result was a wall which was somewhat thinner than was the case using wooden studs.
This tended to increase the sound transfer through the walls. In addition, the existence of a continuous metal web extending from one side of the wall to the other tended to assist in transferring sound.
A further and more serious disadvantage arose during installation of the drywall. When the drywall is installed on such metal studs, the workman uses an electrical screwdriver similar to a power drill, and a self boring screw. The screw has a particular form of self boring screw point which is intended to be applied directly to the sheet metal of the stud, and to pierce its own hole through the stud, after which it will tighten up and secure the drywall panel to the stud. These screws have proved most satisfactory. However, where the thickness of the sheet metal in the metal stud is reduced, for reasons of economy, the side wall of the stud become relatively flexible. As a result, when the drywall workmen are inserting the screws, as they press the screw point against the side wall of the stud the side wall tends to flex. This then allows the screw to slip to one side, consequently damaging the drywall, and leading to a slow down in work. As a result, the thinner gauge drywall studs of this type have caused various problems.
Clearly however, it is desirable as far as possible to reduce the thickness of the gauge of sheet metal used in such studs, providing the disadvantages listed above can be avoided.